Most penetrating thoracic injuries are caused by knives, which cause tissue injueyr with sharp cutting edge or point. When the knife stabs into the mediastinum, it may damage important structures such as the heart, aorta, pulmonary artery, esophagus and trachea, and quickly becomes fatal. Therefore, thoracic trauma is usually associated with complications of lung contusion, cardiac tamponade, pneumomediastinum, esophageal injury, spinal cord injury, bone injury and vascular injury. Physical examination has limited use in the assessment of patients with penetrating thoracic trauma. Imaging tools play an important role in the diagnosis and classification of trauma patients[5, 6]. Radiologists should be familiar with imaging of penetrating thoracic trauma and associated complications.
CT has become the preferred method for evaluating patients with penetrating thoracic injury, which can further reveal hemodynamically stable but life-threatening injuries that are but otherwise not recognized on chest radiographs. The diagnostic rate of chest CT was 38%-81% higher than that of chest radiography. On the one hand, the most common radiographic manifestations of penetrating trauma are pneumothorax and hemothorax, both of which are highly sensitive to CT, even small amounts can be clearly displayed. On the other hand, the knife wound tracks through the lung can be well demonstrated by CT, especially when deep tissue, blood vessels or lung is suspected to be involved in the injury. Therefore, images should be examined in the bone and lung windows to precisely determine the extent of the wound and its relationship to the mediastinum. Furthermore, CT imaging of coronal and sagittal reconstructions can better describe the injury of lung, trachea, heart, great vessels, and the relationship with the knife. In addition, CT angiography (CTA) can be performed to assess active bleeding in stable patients with vascular damage. In general, CT is an optimal option for visualizing pulmonary contusion, pneumothorax, rib fractures and major vascular injuries caused by wound penetration. Moreover, CT has advantages of high accuracy, high sensitivity, high accessibility, low cost and time saving, which can provide information for further diagnosis and intervention.
The clinical manifestations of thoracic stab wounds are varied, from no intrathoracic injury to extensive injury of large vessels, even threatening life. In such cases, it is important to avoid iatrogenic injuries, especially those during transportation. Foreign bodies should be removed as soon as possible to prevent further damage to the heart. If there is a possible or a definite organ injury, liquid support should be given immediately and the patient should be moved to the operating room promptly. The general rule of treatment of penetrating trauma is to avoid deep exploration when assessing the wound site, do not take out the penetration object before accurate diagnosis, and be ready to intubate at any time to ensure the safety of the respiratory tract.